1. Field of the Invention
The present invention relates to a USB transmission line having switching function and, more particularly, to a transmission line whose two ends are connected with USB connectors to have both unidirectional transmission and bi-directional transmission functions.
2. Background of the Invention
Nowadays, various kinds of wired communication electronic equipments like computers, modems, telephones, or facsimile apparatuses inevitably need to use transmission lines of appropriate length to achieve electric connection.
Universal serial bus (USB) transmission lines are a common kind of transmission lines. As shown in FIG. 1, a conventional USB transmission line comprises a transmission line 10a and two connectors 20a and 30a connected at two ends of the transmission line 10a. The two connectors 20a and 30a are USB connectors.
Conventional USB transmission lines can be approximately divided into unidirectional transmission type and bi-directional transmission type. Either the unidirectional transmission type or the bi-directional transmission type has only a single transmission function. That is, a unidirectional USB transmission line cannot be used for bi-directional transmission, while a bi-directional USB transmission line cannot be used for unidirectional transmission. Therefore, the USB transmission line has a limited usage, and cannot be flexibly utilized, resulting in inconvenience in use.
Accordingly, the above conventional USB transmission lines have inconvenience and drawbacks in practical use. The present invention aims to resolve the problems in the prior art.
The primary object of the present invention is to provide a USB transmission line having switching function, wherein a circuit unit having the switching function of unidirectional transmission and bi-directional transmission is disposed on a USB transmission line. A switch can be used to control the use of a unidirectional transmission circuit or a bi-directional transmission circuit so that the USB transmission line can flexibly select the unidirectional transmission function or the bi-directional transmission function. The USB transmission line can thus have both unidirectional transmission and bi-directional transmission functions, resulting in more convenient, more flexible, and wider use.
To achieve the above object, the present invention provides a USB transmission line having switching function, which comprises a transmission line, a first connector, a second connector, and a circuit unit having switching function of unidirectional transmission and bi-directional transmission. The first and second connectors are USB connectors, and are connected at two ends of the transmission line. The circuit unit is disposed on the transmission line between the first and second connectors.
The various objects and advantages of the present invention will be more readily understood from the following detailed description when read in conjunction with the appended drawing, in which: